feat: implement customizable funnel stages per tenant

- Modified attendances.funnel_stage in DB from ENUM to VARCHAR.

- Created tenant_funnels table and backend API routes to manage custom stages.

- Added /admin/funnels page for Admins/Managers to create, edit, order, and color-code their funnel stages.

- Updated Dashboard, UserDetail, and AttendanceDetail to fetch and render dynamic funnel stages instead of hardcoded enums.

- Added defensive checks and logging to GET /users/:idOrSlug to fix sporadic 500 errors during impersonation handoffs.

test-b64.js

@@ -0,0 +1,8 @@
+const token = "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpZCI6InVfMTIzNDUiLCJ0ZW5hbnRfaWQiOiJzeXN0ZW0ifQ.XYZ";
+const base64Url = token.split('.')[1];
+const base64 = base64Url.replace(/-/g, '+').replace(/_/g, '/');
+console.log(base64);
+const jsonPayload = decodeURIComponent(atob(base64).split('').map(function(c) {
+    return '%' + ('00' + c.charCodeAt(0).toString(16)).slice(-2);
+}).join(''));
+console.log(JSON.parse(jsonPayload));